JP4873205B2 - Polymerizable liquid crystal composition and optical element - Google Patents

Description

【００３２】
【化２】

【００３３】
【化３】

【００３４】
【化４】

【００３５】
【化５】

【００３６】
【化６】

【００３７】
【化７】

【００３８】
【化８】

【００３９】
【化９】

【００４０】
【化１０】

【００４１】
【化１１】

【００４２】
【化１２】

【００４３】
【化１３】

【００４４】
【化１４】

【００４５】
【化１５】

【００４６】
【化１６】

【００４７】
【化１７】

【００４８】
【化１８】

【００４９】
【化１９】

【００５０】
【化２０】

【００５１】
【化２１】

【００５２】
【化２２】

【００５３】
【化２３】

【００５４】
【化２４】

【００５５】
【化２５】

【００５６】
【化２６】

【００５７】
【化２７】

【００５８】
【化２８】

【００５９】
【化２９】

【００６０】
【化３０】

【００６１】
【化３１】

【００６２】
【化３２】

【００６３】
【化３３】

【００６４】
（式（１）〜（４４６）中の芳香環、脂環、複素環及び縮合環は、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）
【００６５】
具体的には、本発明で使用される重合性液晶化合物としては、一般式（１）で表わされる重合性液晶化合物の中でも、下記一般式（４）及び（５）、
【化３４】

【００６６】
【化３５】

【００６７】
（式中、Ｘは、水素原子又はメチル基を表わし、Ｙ３は、単結合、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−、−Ｃ≡Ｃ−及び−ＣＨ₂ＣＨ₂−からなる群から選ばれる連結基を表わし、Ｒは、水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｑは、１〜２０の整数を表わし、ｍは、２〜１５の整数を表わし、ｐは、０又は１の整数を表わす。また、１，４−シクロへキシレン基及び１，４−フェニレン基は、各々独立的に、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）
で表わされる重合性液晶化合物、
【００６８】
下記一般式（６）、（７）及び（８）、
【化３６】

【００６９】
【化３７】

【００７０】
【化３８】

（式中、Ｘは、水素原子又はメチル基を表わし、Ｙ３及びＹ４は、おのおの独立的に、単結合、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−、−Ｃ≡Ｃ−及び−ＣＨ₂ＣＨ₂−からなる群から選ばれる連結基を表わし、Ｒは、水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｑは、１〜２０の整数を表わし、ｍは、３〜１６の整数を表わし、ｐは、０又は１の整数を表わす。また、１，４−フェニレン基は、各々独立的に炭素原子数１〜７のアルキル基、アルコキシ基、アルカノイル基、又はシアノ基、ハロゲン原子で一つ以上置換されていても良い。）
で表わされる重合性液晶化合物、下記一般式（９）及び（１０）、
【００７１】
【化３９】

【００７２】
【化４０】

（式中、Ｘは、水素原子又はメチル基を表わし、Ｒは、水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｑは、１〜２０の整数を表わし、ｍは、２〜１５の整数を表わす。また、１，４−シクロへキシレン基及び１，４−フェニレン基は、各々独立的に、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）で表わされる重合性液晶化合物、一般式（１１）、（１２）、（１３）、（１４）及び（１５）、
【００７３】
【化４１】

【００７４】
【化４２】

【００７５】
【化４３】

【００７６】
【化４４】

【００７７】
【化４５】

【００７８】
（式中、Ｘは、水素原子又はメチル基を表わし、Ｙ３、Ｙ４及びＹ５は、おのおの独立的に、単結合、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−、−Ｃ≡Ｃ−及び−ＣＨ２ＣＨ２−からなる群から選ばれる連結基を表わし、ｑは、１〜２０の整数を表わし、ｍは、３〜１６の整数を表わし、環Ｊは、１，４−シクロヘキシレン基、１，４−フェニレン基を表わし、Ｒは、水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｐ及びｓは、おのおの独立的に、０又は１を表わす。また、１，４−シクロへキシレン基、１，４−フェニレン基は、各々独立的に、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）
で表わされる重合性液晶化合物が特に好ましい。
【００７９】
本発明の化合物の好ましい例として、（メタ）アクリレート化合物を挙げてきたが、反応性基としてエポキシ基を有する化合物も好ましい。そのような化合物としては、例えば、以下の一般式（１６）及び（１７）で表わされる化合物を挙げることができる。
【００８０】
【化４６】

【００８１】
【化４７】

【００８２】
（式中、Ｙ３、Ｙ４及びＹ５は、おのおの独立的に、単結合、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−、−Ｃ≡Ｃ−及び−ＣＨ２ＣＨ２−からなる群から選ばれる連結基を表わし、ｑは、１〜２０の整数を表わし、ｍは、２〜１５の整数を表わし、ｎは、３〜１６の整数を表わし、環Ｊは、１，４−シクロヘキシレン基、１，４−フェニレン基を表わし、Ｒは水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｐ及びｓは、おのおの独立的に、０又は１を表わす。また、１，４−シクロヘキシレン基及び１，４−フェニレン基は、おのおの独立的に、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）
【００８３】
本発明の化合物の好ましい例として、反応性基としてビニルオキシ基を有する化合物も好ましい。そのような化合物としては、例えば、以下の一般式（１８）及び（１９）で表わされる化合物を挙げることができる。
【００８４】
【化４８】

【００８５】
【化４９】

【００８６】
（式中、Ｙ３、Ｙ４及びＹ５は、おのおの独立的に、単結合、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−、−Ｃ≡Ｃ−及び−ＣＨ２ＣＨ２−からなる群から選ばれる連結基を表わし、ｑは、１〜２０の整数を表わし、ｍは、２〜１５の整数を表わし、環Ｊは、１，４−シクロヘキシレン基、１，４−フェニレン基を表わし、Ｒは、水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｐ及びｓは、おのおの独立的に、０又は１を表わす。また、１，４−シクロヘキシレン基及び１，４−フェニレン基は、おのおの独立的に、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）
【００８７】
本発明の化合物の好ましい例として、反応性基としてマレイミド基を有する化合物も好ましい。そのような化合物としては、例えば、以下の一般式（２０）及び（２１）で表わされる化合物を挙げることができる。
【００８８】
【化５０】

【００８９】
【化５１】

【００９０】
（式中、Ｙ３、Ｙ４及びＹ５は、おのおの独立的に、単結合、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−、−Ｃ≡Ｃ−及び−ＣＨ２ＣＨ２−からなる群から選ばれる連結基を表わし、ｑは、１〜２０の整数を表わし、ｍは、２〜１５の整数を表わし、環Ｊは、１，４−シクロヘキシレン基、１，４−フェニレン基を表わし、Ｒは、水酸基、シアノ基、ハロゲン基、炭素原子数１〜７のアルキル基、アルコキシ基又はアルカノイル基を表わし、ｐ及びｓは、おのおの独立的に、０又は１を表わす。また、１，４−シクロヘキシレン基及び１，４−フェニレン基は、おのおの独立的に、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良い。）
【００９１】
本発明の液晶組成物は、光学素子の作製に応用する場合には、室温で、典型的には２５℃において液晶相を呈することが好ましい。
【００９２】
本発明の液晶組成物は、通常この技術分野で液晶相と認識される相を示す組成物であればよい。そのような組成物の中でも、液晶相として、ネマチック相、スメクチックＡ相、（キラル）スメクチックＣ相、コレステリック相を発現するものが好ましい。それらの中でも、ネマチック相は良好な配向性を有するため、特に好ましい。また、（キラル）スメクチックＣ相を示す場合には、該（キラル）スメクチックＣ相の温度領域より高い温度領域でスメクチックＡ相を、該スメクチックＡ相の温度領域より高い温度領域でネマチック相を、それぞれ発現する液晶組成物は、良好な配向性を得られる傾向にあるので好ましい。
【００９３】
本発明の液晶組成物は、更に公知慣用の液晶化合物を併用して用いることも出来る。中でも、一分子中に１個の（メタ）アクリロイルオキシ基、（メタ）アクリルアミド基、ビニル基、エポキシ基、エチニル基、メルカプト基、ビニルオキシ基及びマレイミド基からなる群から選ばれる重合性官能基を有する液晶性化合物が好ましい。このような重合性液晶化合物としては、例えば、一般式（３）
【００９４】
【化５２】

【００９５】
（式中、Ｘは、水素原子又はメチル基を表わし、Ｍは芳香環、脂環、複素環及び縮合環からなる群から選ばれる同一又は異なる２〜１６個の環を有するメソゲン部を表し、Ｙ₃は、単結合、−Ｏ−、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−及び−ＣＨ＝ＣＨ−Ｃ（＝Ｏ）Ｏ−からなる群から選ばれる連結基を表わし、Ｚ₁は、水素原子、ハロゲン原子、シアノ基、又は炭素原子数１〜２０の炭化水素基を表わす。）
で表される重合性液晶化合物が挙げられ、好ましく用いられる。
【００９６】
上記一般式（２）において、メソゲン部Ｍは、上記一般式（１）におけるメソゲン部Ｍと同様の構造を示す。
【００９７】
具体的には、例えば、下記一般式（２２）
【化５３】

（式中、Ｘは、水素原子又はメチル基を表わし、ｒは、０又は１の整数を表わし、６員環Ｋ、Ｌ、Ｍは、おのおの独立的に、１，４−フェニレン基、ピリジン−２，５−ジイル基、ピリミジン−２，５−ジイル基、ピラジン−２，５−ジイル基、１，４−シクロヘキシレン基、１つ又は隣接しない２つのＣＨ₂ 基が酸素又は硫黄原子で置換された１，４−シクロヘキシレン基、１，４−シクロヘキセニル基を表わし、これらの６員環Ｋ、Ｌ及びＭは、さらに、シアノ基、ハロゲン原子、炭素原子数１〜７のアルキル基、アルコキシ基及びアルカノイル基からなる群から選ばれる一つ以上の置換基で置換されていても良く、Ｙ₁及びＹ₂は、おのおの独立的に、単結合、−ＣＨ₂ＣＨ₂−、−ＣＨ₂Ｏ−、−ＯＣＨ₂−、−Ｃ（＝Ｏ）Ｏ−、−ＯＣ（＝Ｏ）−、−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−（ＣＨ₂）₄−、−ＣＨ₂ＣＨ₂ＣＨ₂Ｏ−、−ＯＣＨ₂ＣＨ₂ＣＨ₂−、−ＣＨ＝ＣＨ−ＣＨ₂ＣＨ₂−、−ＣＨ₂ＣＨ₂−ＣＨ＝ＣＨ−、−ＣＨ＝ＣＨ−Ｃ（＝Ｏ）Ｏ−及び−ＯＣ（＝Ｏ）−ＣＨ＝ＣＨ−からなる群から選ばれる連結基を表わし、Ｙ₃は、単結合、−Ｏ−、−ＯＣ（＝Ｏ）−、−Ｃ（＝Ｏ）Ｏ−及び−ＣＨ＝ＣＨ−Ｃ（＝Ｏ）Ｏ−からなる群から選ばれる連結基を表わし、Ｚ₁は、水素原子、ハロゲン原子、シアノ基、炭素原子数１〜２０の炭化水素基又は炭素原子２〜２０のアルケニル基を表わす。）
で表わされる液晶性（メタ）アクリレートが好ましい。
【００９８】
本発明の液晶組成物に含有させることができる一般式（２２）で表わされる液晶性（メタ）アクリレート化合物としては、一般式（２３）、
【００９９】
【化５４】

【０１００】
（式中、Ｘは、水素原子又はメチル基を表わし、Ｒ₁は、炭素原子数１〜１０のアルキル基を表わす。）
で表わされる化合物や、一般式（２４）、
【０１０１】
【化５５】

【０１０２】
（式中、Ｘは、水素原子又はメチル基を表わし、Ｒ₂は、炭素原子数１〜１０のアルキル基を表わす。）
で表わされる化合物が好ましい。これらの一般式（２３）で表わされる化合物や一般式（２４）で表わされる化合物は、単独で用いても良いし、組み合わせて用いても良い。組み合わせて用いる場合、一般式（２３）と一般式（２４）で表わされる化合物の濃度を等しくすることが好ましい。また、その用いる量としては、９０重量％以下が好ましく、８０重量％以下がさらに好ましい。しかしながら、本発明の液晶組成物において使用することができる化合物は、これらの化合物に限定されるものではない。
【０１０３】
一般式（２２）で表わされる化合物の具体的なものとして、式（ａ-1）〜式（ａ-25）で表わされる化合物が挙げられる。なお、例示した式（ａ-1）〜式（ａ-25）で表わされる化合物の構造式の下に、相転移温度を示した。（式中、シクロヘキサン環はトランスシクロヘキサン環を表わす。また、数字は相転移温度を表わし、Ｃは結晶相、Ｎはネマチック相、Ｓはスメクチック相、Ｉは等方性液体相をそれぞれ表わす。）
【０１０４】
【化５６】

【０１０５】
【化５７】

【０１０６】
【化５８】

【０１０７】
【化５９】

【０１０８】
また、本発明の液晶組成物には、一般式（２２）で表わされる（メタ）アクリレート化合物以外にも、他の単官能（メタ）アクリレート化合物を含有させることもできる。そのような化合物としては、例えば、以下の式（a-26）〜（a-35）で表わされる化合物が挙げられる。しかしながら、本発明の液晶組成物において使用することができる化合物はこれらに限定されるものではない。なお、例示した式（ａ-26）〜式（ａ-35）で表わされる化合物の構造式の下に、相転移温度を示した。（式中、シクロヘキサン環は、トランスシクロヘキサン環を表わす。数字は相転移温度を表わし、Ｃは結晶相、Ｎはネマチック相、Ｓはスメクチック相、Ｉは等方性液体相をそれぞれ表わす。）
【０１０９】
【化６０】

【０１１０】
【化６１】

【０１１１】
また、本発明の液晶組成物には、上記に掲げた化合物以外に、側鎖に液晶性骨格を有する（メタ）アクリレート化合物を含有させることもできる。そのような化合物としては、例えば、以下の式（ａ-36）〜式（ａ-45）で表わされる化合物を挙げることができる。（式中、シクロヘキサン環は、トランスシクロヘキサン環を表わす。数字は相転移温度を表わし、Ｃは結晶相、Ｎはネマチック相、Ｓはスメクチック相、Ｉは等方性液体相をそれぞれ表わす。）
【０１１２】
【化６２】

【０１１３】
【化６３】

【０１１４】
さらに、本発明の液晶組成物には、上記に挙げた化合物以外にも、本発明の液晶組成物に、他の液晶性（メタ）アクリレート化合物を含有させることもできる。そのような化合物としては、例えば、以下の式（ａ-46）〜式（ａ-61）で表わされる化合物を挙げることができる。
【０１１５】
【化６４】

【０１１６】
【化６５】

（式中、Ｘ⁶及びＸ⁷は、おのおの独立的に、水素原子又はメチル基を表わし、ｓ及びｔは、おのおの独立的に、２〜１８の整数を表わす）。
【０１１７】
また、本発明の液晶組成物には、重合性官能基を有していない液晶化合物を用途に応じて添加することもできる。しかしながら、液晶組成物を用いて作製する高分子の耐熱性を確保する観点から、その添加量は８０重量％以下が好ましく、３０重量％以下がさらに好ましく、１０重量％以下が特に好ましい。
【０１１８】
また、本発明の液晶組成物には、重合性官能基を有する化合物であって、液晶性を示さない化合物を添加することもできる。このような化合物としては、通常、この技術分野で高分子形成性モノマーあるいは高分子形成性オリゴマーとして認識されるものであれば特に制限なく使用することができる。
【０１１９】
本発明の液晶組成物は、液晶相の温度領域で活性エネルギー線を照射して、組成物中の重合性化合物を重合させることを目的としている。従って、活性エネルギー線照射工程における、望ましくない熱重合の誘起を避け、均一性に優れた高分子を製造するために、本発明の液晶組成物は、室温（典型的には２５℃）又は室温付近で液晶性を示すものが好ましい。例えば、（キラル）スメクチックＣ相において、本発明の液晶組成物に活性エネルギー線を照射して、組成物中の重合性化合物を重合させる場合、室温又は室温付近で（キラル）スメクチックＣ相を発現するものが好ましい。
【０１２０】
また、本発明の液晶組成物には、液晶骨格の螺旋構造を内部に有する高分子を得ることを目的として、キラル（光学活性）化合物を添加することもできる。そのような目的で使用するキラル化合物は、それ自体が液晶性を示す必要は無く、また、重合性官能基を有していても、有していなくても良い。また、キラル化合物の螺旋の向きは、重合体の使用用途によって適宜選択することができる。
【０１２１】
そのようなキラル化合物としては、例えば、キラル基としてコレステリル基を有するペラルゴン酸コレステロール、ステアリン酸コレステロール、キラル基として２−メチルブチル基を有するビーディーエイチ社（ＢＤＨ社；イギリス国）製の「ＣＢ−15」、「Ｃ−15」、メルク社（ドイツ国）製の「Ｓ−１０８２」、チッソ社製の「ＣＭ−19」、「ＣＭ−20」、「ＣＭ」；キラル基として１−メチルヘプチル基を有するメルク社製の「Ｓ−８１１」、チッソ社製の「ＣＭ−21」、「ＣＭ−22」、などを挙げることができる。
【０１２２】
キラル化合物を添加する場合の好ましい添加量は、液晶組成物の用途によるが、重合して得られる重合体の厚み（ｄ）を重合体中での螺旋ピッチ（Ｐ）で除した値（ｄ／Ｐ）が０．１〜１００の範囲となる量が好ましく、０．１〜２０の範囲となる量がさらに好ましい。
【０１２３】
更に本発明の液晶組成物には、その重合反応性を向上させることを目的として、熱重合開始剤、光重合開始剤等の重合開始剤を添加することもできる。
熱重合開始剤としては、例えば、過酸化ベンゾイル、ビスアゾブチロニトリル等が挙げられる。また、光重合開始剤としては、例えば、ベンゾインエーテル類、ベンゾフェノン類、アセトフェノン類、ベンジルケタール類等が挙げられる。熱重合開始剤あるいは光重合開始剤を添加する場合の添加量は、液晶組成物に対して、１０重量％以下が好ましく、５重量％以下が特に好ましく、０．５〜１．５重量％の範囲が更に好ましい。
【０１２４】
また、本発明の液晶組成物には、その保存安定性を向上させるために、安定剤を添加することもできる。使用できる安定剤としては、例えば、ヒドロキノン、ヒドロキノンモノアルキルエーテル類、第三ブチルカテコール類、ピロガロール類、チオフェノール類、ニトロ化合物類、β−ナフチルアミン類、β−ナフトール類等が挙げられる。安定剤を使用する場合の添加量は、液晶組成物に対して、１重量％以下が好ましく、０．５重量％以下が特に好ましい。
【０１２５】
以上のように、本発明の液晶組成物には、一般式（１）、又は、（２）で表わされる液晶性（メタ）アクリレート以外に、重合性官能基を有する液晶化合物、重合性官能基を有さない液晶化合物、液晶性を示さない重合性化合物、重合開始剤、安定剤を適宜組み合わせて添加してもよいが、少なくとも得られる液晶組成物の液晶性が失われないよう、各成分の添加量を調整する必要がある。
【０１２６】
また、本発明の液晶組成物を偏光フィルムや配向膜の原料、又は印刷インキ及び塗料、保護膜等の用途に利用する場合には、その目的に応じて、金属、金属錯体、染料、顔料、色素、蛍光材料、燐光材料、界面活性剤、レベリング剤、チキソ剤、ゲル化剤、多糖、紫外線吸収剤、赤外線吸収剤、抗酸化剤、イオン交換樹脂、酸化チタンの如き金属酸化物、などを添加することもできる。
【０１２７】
本発明の液晶化合物を含有する液晶組成物は、重合させて重合体とすることによって、位相差板、偏光板、偏光プリズム、導波路、圧電素子、非線形光学素子、各種光フィルター、コレステリック液晶相等の選択反射を利用した液晶顔料、液晶−樹脂複合ディスプレー、ホログラフィック液晶ディスプレー、高分子安定化液晶（強誘電性液晶、反強誘電性液晶）ディスプレー、光ファイバー等の被覆剤などの各種の用途に応用することができる。中でも、本発明の液晶組成物を配向させた状態において、重合させた重合体は、物理的性質に異方性を有しており、有用である。このような重合体は、例えば、本発明の重合性液晶組成物を、布等で表面をラビング処理した基板、有機薄膜を形成した基板の表面を布等でラビング処理した基板、あるいはＳｉＯ₂ を斜方蒸着した配向膜を有する基板上に担持させるか、基板間に挟持させた後、重合性化合物を重合させることによって製造することができる。
【０１２８】
重合性液晶組成物を基板上に担持させる際の方法としては、例えば、スピンコーティング、ダイコーティング、エクストルージョンコーティング、ロールコーティング、ワイヤーバーコーティング、グラビアコーティング、スプレーコーティング、ディッピング、プリント法、などが挙げられる。また、コーティングの際、重合性液晶組成物に有機溶媒を添加することもできる。そのような目的で使用することができる有機溶媒としては、例えば、酢酸エチル、テトラヒドロフラン、トルエン、ヘキサン、メタノール、エタノール、ジメチルホルムアミド、塩化メチレン、イソプロパノール、アセトン、メチルエチルケトン、アセトニトリル、セロソルブ類、などが挙げられる。これらの有機溶媒は、単独で用いることも、２種類以上を組み合わせて用いることもでき、その蒸気圧と重合性液晶組成物の溶解性を考慮し、適宜選択すれば良い。また、有機溶剤の添加量は、コーティング材料の９０重量％以下が好ましい。９０重量％以上になると、得られる膜厚が薄くなってしまう傾向にあるので好ましくない。
【０１２９】
添加した有機溶媒を揮発させる方法としては、自然乾燥、加熱乾燥、減圧乾燥、減圧加熱乾燥を用いることができる。重合性液晶材料の塗布性をさらに向上させるために、基板上にポリイミド薄膜等の中間層を設ける方法、重合性液晶材料にレベリング剤を添加する方法も有効である。特に、基板上にポリイミド薄膜等の中間層を設ける方法は、重合性液晶材料を重合させて得られる高分子と基板の密着性が良くない場合に、密着性を向上させる手段としても有効である。
【０１３０】
重合性液晶材料を基板間に挟持させる方法としては、毛細管現象を利用した注入法が挙げられる。基板間に形成された空間を減圧し、その後、重合性液晶材料を注入する手段も有効である。
【０１３１】
ラビング処理あるいはＳｉＯ₂ の斜方蒸着以外の配向処理の方法として、液晶材料の流動配向を利用する方法、電場又は磁場の利用する方法が挙げられる。これらの配向手段は、単独で用いることも、２種類以上の方法を組み合わせて用いることもできる。
【０１３２】
さらに、ラビングに代わる配向処理方法として、光配向法を用いることもできる。この方法は、例えば、ポリビニルシンナメート等の分子内に光二量化反応する官能基を有する有機薄膜、光で異性化する官能基を有する有機薄膜又はポリイミド等の有機薄膜に、偏光した光、好ましくは偏光した紫外線を照射することによって、配向膜を形成するものである。この光配向法に光マスクを適用することにより、配向のパターン化が容易に達成できるので、高分子内部の分子配向も精密に制御することができる。
【０１３３】
基板の形状としては、平板の他、曲面を有するものであっても良い。基板を構成する材料は、有機材料、無機材料を問わずに用いることができる。基板の材料となる有機材料としては、例えば、ポリエチレンテレフタレート、ポリカーボネート、ポリイミド、ポリアミド、ポリメタクリル酸メチル、ポリスチレン、ポリ塩化ビニル、ポリテトラフルオロエチレン、ポリクロロトリフルオロエチレン、ポリアリレート、ポリスルホン、トリアセチルセルロース、セルロース、ポリエーテルエーテルケトン等が挙げられ、また、無機材料としては、例えば、シリコン、ガラス、方解石等が挙げられる。
【０１３４】
これらの基板を布等でラビングすることによって適当な配向性を得られない場合、公知の方法に従ってポリイミド薄膜又はポリビニルアルコール薄膜等の有機薄膜を基板表面に形成し、これを布等でラビングしても良い。また、通常のツイステッド・ネマチック（ＴＮ）素子又はスーパー・ツイステッド・ネマチック（ＳＴＮ）素子で使用されているプレチルト角を与えるポリイミド薄膜は、高分子内部の分子配向構造を更に精密に制御することができることから、特に好ましい。
【０１３５】
また、電場によって配向状態を制御する場合には、電極層を有する基板を使用する。この場合、電極上に前述のポリイミド薄膜等の有機薄膜を形成することが好ましい。
【０１３６】
液晶組成物の配向状態としては、液晶の技術分野で一般的に知られている種々の配向状態でよく、例えば、ホモジニアス（水平）配向、傾いたホモジニアス配向、ホメオトロピック（垂直）配向、傾いたホメオトロピック配向、ハイブリッド配向、ツイステッドネマチック配向、スーパーツイステッドネマチック配向状態を挙げることができる。また、これらの配向の組み合わせや、場所ごとに配向状態を変えてパターン化しても良い。
【０１３７】
傾いたホモジニアス配向及び傾いたホメオトロピック配向の場合、双方の場合とも基板面と液晶分子長軸のなす角度が０度又は９０度以外になっている状態を意味する。基板面と液晶分子長軸のなす角度は、得られる重合体の用途・機能によって選択すれば良い。基板面と液晶分子長軸のなす角度を１０〜８０度、さらに好ましくは、２０〜７０度の範囲に設定した場合、得られる重合体は、液晶ディスプレイの視野角を広く改善するための光学部材として使用することができる。
【０１３８】
また、液晶組成物の配向状態をハイブリッド配向にした場合も、得られる重合体は、液晶ディスプレイの視野角を広く改善するための光学部材として使用可能である。また、基板面と液晶分子長軸のなす角度を３０〜６０度、さらに好ましくは、４０〜５０度、特に好ましくは４５度に設定した場合、得られる重合体に、偏光分離能を効率良く付与することができる。このような重合体は、偏光分離素子や光学的ローパスフィルターとして有用である。
【０１３９】
また、液晶組成物の配向状態をハイブリッド配向にした場合も、得られる重合体は、偏光光学素子や光学的ローパスフィルターとして有用である。
一方、ツイステッドネマチック配向、スーパーツイステッドネマチック配向、コレステリック配向に代表されるような螺旋構造を有する配向構造も有用である。ねじり角度を６０〜２７０度に設定した場合、得られる重合体は、液晶表示素子の光学補償用途に有用である。また、螺旋ピッチを調節し、特定の波長領域を選択的に反射するように設定した場合、得られる重合体は、ノッチフィルターや反射型カラーフィルターとして有用である。
【０１４０】
また、選択的に反射する波長領域を赤外線の領域に設定した場合、得られる重合体は、熱線カットフィルターとして有用である。また、ホモジニアス配向、ホメオトロピック配向状態にした場合、得られる重合体は、プラスチックを延伸処理したものと比較して、屈折率の異方性が大きいため、同じ屈折率の異方性を示すものを薄く設計できるという利点がある。また、液晶セル内部に、光学補償板を作り込める可能性もある。反射型液晶表示素子の光学補償に用いる場合、この特性は重要であり、特に１／４波長板として極めて有用である。
【０１４１】
本発明の液晶組成物を重合させる方法としては、迅速に重合する点で、紫外線又は電子線等の活性エネルギー線を照射することによって重合させる方法が好ましい。紫外線を使用する場合、偏光光源を用いても良いし、非偏光光源を用いても良い。また、液晶組成物を２枚の基板間に挟持させて状態で重合を行なう場合には、少なくとも照射面側の基板は、活性エネルギー線に対して適当な透明性が与えられていなければならない。また、光照射時にマスクを用いて特定の部分のみを重合させた後、電場や磁場又は温度等の条件を変化させることにより、未重合部分の配向状態を変化させて、さらに活性エネルギー線を照射して重合させるという手段を用いても良い。また、照射時の温度は、本発明の液晶組成物の液晶状態が保持される温度範囲内であることが好ましい。
【０１４２】
特に、光重合によって高分子を製造しようとする場合には、意図しない熱重合の誘起を避ける意味からも可能な限り、室温に近い温度、即ち、典型的には２５℃での温度で重合させることが好ましい。活性エネルギー線の強度は、０．１ｍＷ／cm²〜２Ｗ／cm²の範囲が好ましい。強度が０．１ｍＷ／cm²未満の場合、光重合を完了させるのに多大な時間が必要になり、生産性が悪化する傾向にあり、２Ｗ／cm²を超える強度では、重合性液晶組成物が劣化する傾向にあるので、好ましくない。
【０１４３】
本発明の重合性液晶組成物に活性光線を照射した後、得られた重合体の初期特性変化を軽減し、安定的な特性発現を図ることを目的として、熱処理を施すこともできる。熱処理の温度は、５０〜２５０℃の範囲で、熱処理時間は３０秒〜１２時間の範囲が好ましい。
【０１４４】
このような方法によって製造される本発明の重合性液晶組成物からなる重合体は、基板から剥離して単体で用いることも、基板から剥離せずにそのまま用いることもできる。また、本発明の重合性液晶組成物からなる重合体は、２つ以上を積層して用いることも、他の基板に貼り合わせて用いることもできる。
【０１４５】
【実施例】
以下、実施例を用いて、本発明を更に詳細に説明する。しかしながら、本発明はこれらの実施例の限定されるものではない。なお、以下の実施例におけるヘイズの測定は、補償法（ＪＩＳ、Ｋ７３６１）で行った。
【０１４６】
（実施例１）〔液晶組成物の調製（１）〕
式（ａ−１）
【０１４７】
【化６６】

で表わされる液晶性アクリレート化合物４５重量部、式（ａ−４）
【０１４８】
【化６７】

で表わされる液晶性アクリレート４５重量部及び式（ａ−６２）
【０１４９】
【化６８】

で表わされる液晶性アクリレート１０重量部から成る組成物（Ａ）を調製した。組成物（Ａ）は、室温（２５℃）でネマチック液晶相を呈した。また、５８９ｎｍで測定したｎ_e（異常光の屈折率）は１．６７０２で、ｎ_o（常光の屈折率）は１．５１１、複屈折率は０．１５９２であった。
【０１５０】
（実施例２）〔液晶組成物の調製（２）〕
実施例１での式（ａ−１）で表わされる液晶性アクリレート化合物３５重量部、式（ａ−４）で表わされる液晶性アクリレート３５重量部及び式（ａ−６２）で表わされる液晶性アクリレート３０重量部から成る組成物（Ｂ）を調製した。組成物（Ｂ）は、室温（２５℃）でネマチック液晶相を呈した。また、５８９ｎｍで測定したｎ_e（異常光の屈折率）は１．６８１３で、ｎ_o（常光の屈折率）は１．５１２、複屈折率は０．１６９３であった。
【０１５１】
（比較例１）〔液晶組成物の調製（３）〕
実施例１での式（ａ−１）で表わされる液晶性アクリレート化合物５０重量部及び式（ａ−４）で表わされる液晶性アクリレート５０重量部から成る組成物（Ｃ）を調製した。組成物（Ｃ）は、室温（２５℃）でネマチック液晶相を呈した。ネマチック相−等方性液体相転移温度は４６℃であった。また、５８９ｎｍで測定したｎ_e（異常光の屈折率）は１．６６２で、ｎ_o（常光の屈折率）は１．５１０、複屈折率は０．１５２であった。
【０１５２】
（実施例３）〔光学異方体の作製（１）〕
実施例１で調製した組成物（Ａ）９９重量部、光重合開始剤「イルガキュアー６５１」（チバガイギー社製）１重量部からなる組成物（Ｄ）を調製した。セルギャップ５及び５０ミクロンのアンチパラレル配向液晶ガラスセル（液晶を一軸配向するよう配向処理を施したガラスセル）に、組成物（Ｄ）を室温にて注入した。注入後、均一な一軸配向が得られていることを確認することができた。次に、室温（２５℃）にてＵＳＨＩＯ社のＵＩＳ−２５１０２を用いて３０ｍＷ／cm²の紫外線を、照射量が９０、１８０及び３６０ｍＪ／cm²なるまで照射して、組成物（Ｄ）を重合させて、重合物を得た。得られた重合物は、方向によって屈折率が異なっており、光学異方体として機能することを確認することができた。ガラスセルに入れたままの重合物の透明性（ヘイズ値）及びリタデーションは表１に示した。
【０１５３】
【表１】
組成物（Ｄ）の重合体のヘイズ及びリタデーション

【０１５４】
（実施例４）〔光学異方体の作製（２）〕
実施例２で調製した組成物（Ｂ）９９重量部、光重合開始剤「イルガキュアー６５１」（チバガイギー社製）１重量部からなる組成物（Ｅ）を調製した。セルギャップ５及び５０ミクロンのアンチパラレル配向液晶ガラスセル（液晶を一軸配向するよう配向処理を施したガラスセル）に、組成物（Ｅ）を室温にて注入した。注入後、迅速に均一な一軸配向が得られていることを確認することができた。次に、室温（２５℃）にてＵＳＨＩＯ社のＵＩＳ−２５１０２を用いて３０ｍＷ／cm²の紫外線を、照射量が９０、１８０及び３６０ｍＪ／cm²なるまで照射して、組成物（Ｅ）を重合させて、重合物を得た。得られた重合物は、方向によって屈折率が異なっており、光学異方体として機能することを確認することができた。ガラスセルに入れたままの重合物のヘイズ及びリタデーションは表２に示した。
【０１５５】
【表２】
組成物（Ｅ）の重合体のヘイズ及びリタデーション

【０１５６】
（比較例２）〔光学異方体の作製（３）〕
比較例１で調製した組成物（Ｃ）９９重量部及び重合開始剤「イルガキュアー６５１」（チバガイギー社製）１重量部からなる組成物（Ｆ）を調製した。セルギャップ５及び５０ミクロンのアンチパラレル配向液晶ガラスセル（液晶を一軸配向するよう配向処理を施したガラスセル）に、組成物（Ｆ）を室温にて注入した。注入後、均一な一軸配向が得られていることを確認することができた。次に、室温（２５℃）にてＵＳＨＩＯ社のＵＩＳ−２５１０２を用いて３０ｍＷ／cm²の紫外線を、照射量が９０、１８０及び３６０ｍＪ／cm²なるまで照射して、組成物（Ｆ）を重合させて、重合物を得た。得られた重合物は、方向によって屈折率が異なっており、光学異方体として機能することを確認することができた。ガラスセルに入れたままの重合物のヘイズ及びリタデーションは表３に示した。
【０１５７】
【表３】
組成物（Ｆ）の重合体のヘイズ及びリタデーション

実施例３、４及び比較例２の結果を表１、２及び３に示したが、本発明の化合物を含有する液晶組成物を用いることにより、重合により作製される重合物のヘイズが低減され、また、リタデーションが改善されたことがわかる。
【０１５８】
【発明の効果】
本発明の重合性液晶組成物は、良好な液晶性を示し、また、重合して得られる重合物のヘイズ及びリタデーションを改善することができる。従って、本発明の化合物は、例えば、位相差板、偏光板、偏光プリズム、導波路、圧電素子、非線形光学素子、各種光フィルター、コレステリック液晶相等の選択反射を利用した顔料、光ファイバー等の被覆剤への応用に極めて有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a phase difference plate, a polarizing plate, a polarizing prism, a waveguide, a piezoelectric element, a nonlinear optical element, various optical filters, a liquid crystal pigment utilizing selective reflection of a cholesteric liquid crystal phase, a liquid crystal-resin composite display, a holographic liquid crystal display The present invention relates to a polymerized liquid crystal composition useful as a coating agent for polymer stabilized liquid crystal (ferroelectric liquid crystal, antiferroelectric liquid crystal) display, optical fiber, and the like, and a polymer obtained by polymerizing the liquid crystal composition.
[0002]
[Prior art]
A liquid crystal compound having a polymerizable functional group (hereinafter referred to as a polymerizable liquid crystal compound) or a polymerizable liquid crystal composition containing such a compound is aligned in a liquid crystal state, and then active energy rays such as ultraviolet rays in the state. , A polymer in which the alignment state structure of liquid crystal molecules is fixed can be produced. The polymer thus obtained has anisotropy of physical properties such as refractive index, dielectric constant, magnetic susceptibility, elastic modulus, and thermal expansion coefficient. It can be applied as a coating agent such as a plate, a polarizing prism, a waveguide, a piezoelectric element, a nonlinear optical element, various optical filters, a pigment using selective reflection of a cholesteric liquid crystal phase, and an optical fiber.
[0003]
As a polymerizable liquid crystal composition used for such applications, JP-A-8-3111 provides a polymerizable liquid crystal composition containing a polymerizable compound having one (meth) acryl group in one molecule. . Although the polymerizable liquid crystal composition disclosed in the publication has a characteristic of exhibiting liquid crystallinity at room temperature, there are problems that a retardation after polymerization is lowered, transparency and mechanical strength are insufficient.
[0004]
[Problems to be solved by the invention]
Therefore, the problem to be solved by the present invention is to provide a polymerizable liquid crystal composition that exhibits good liquid crystallinity and that is excellent in retardation and transparency after polymerization.
[0005]
[Means for Solving the Problems]
As a result of intensive studies on the correlation between the chemical structure and physical properties of the polymerizable liquid crystal composition, the present inventors have found that the polymerizable functional group is bonded to the ring A via a linking chain S1 having a specific structure, The above problem can be solved by providing a composition containing a compound represented by the following general formula (1) in which ring A is bonded to mesogenic moiety M via linking chain S2 having a specific structure. As a result, the present invention has been completed. Therefore, the present invention
(A) General formula (1)
P-S1-A-S2-M (1)
(P represents a polymerizable functional group, A represents a ring selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring, and M represents a group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring. It represents a mesogenic moiety having the same or different 2-16 rings.
S1 is-(CH ₂ ) _w -,-(CH ₂ ) _w O-,-(CH ₂ ) _w C (= O) O- and-(CH ₂ ) _w OC (= O)-(v represents an integer of 1 to 20) represents a connecting chain selected from the group consisting of: S2 represents -C (= O) -O- (CH ₂ ) _m -O-, -O (CH ₂ ) _m -O-C (= O)-, -O-C (= O)-(CH ₂ ) _m -O- and -O (CH ₂ ) _m A connecting chain represented by —C (═O) —O— (n represents an integer of 2 to 15) is represented. )
A polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having one polymerizable functional group in one molecule represented by the formula:
[0006]
In order to solve the above problems, the present invention provides (B) an optical element using the polymerizable liquid crystal composition described in (A).
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The polymerizable liquid crystal composition of the present invention is a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound represented by the following general formula (1).
[0008]
P-S1-A-S2-M (1)
(P represents a polymerizable functional group, A represents a ring selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring, and M represents a group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring. Represents a selected mesogenic moiety having the same or different 2 to 16 rings, and S1 represents a connecting chain composed of at least 1 to 18 atoms selected from carbon, oxygen, silicon and sulfur. , S2 represents a connecting chain whose main chain is composed of 5 to 18 atoms selected from carbon, oxygen, silicon and sulfur.)
[0009]
In the general formula (1), the polymerizable functional group P is not particularly limited as long as it is a polymerizable functional group. Specifically, for example, an acryloyloxy group, a methacryloyloxy group, ClCH═CHC (= O) O-, acrylamide group, methacrylamide group, ClCH = CHC (= O) NH-, vinyl group, CH ₂ = CCl-, CHCl = CH-, epoxy group, ethynyl group, mercapto group, vinyloxy group, maleimide group and the like. Among them, acryloyloxy group, methacryloyloxy group, vinyl group, epoxy group, mercapto group, vinyloxy group and maleimide group are preferable, and acryloyloxy group, methacryloyloxy group, epoxy group, vinyloxy group and maleimide group are particularly preferable.
[0010]
In the general formula (1), S1 represents a connecting chain whose main chain is composed of at least one atom selected from carbon, oxygen, silicon and sulfur. 1-20 are preferable and, as for the number of atoms which comprise connecting chain S1, 1-18 are especially preferable. Examples of the linking chain include an alkyl chain, an alkylene chain, an alkenylene chain, an alkynylene chain, an oxyalkylene chain, and an oxyalkylenoyl chain. Further, these linking chains may have a bond such as an ether bond, a thioether bond, an ester bond, an amide bond, an imine bond, a double bond, or a triple bond.
[0011]
Specifically,-(CH ₂ ) _w -,-(CH ₂ ) _w O-,-(CH ₂ ) _w C (= O) O- and-(CH ₂ ) _w A connecting chain selected from the group consisting of OC (= O)-(v represents an integer of 1 to 20) is preferred, and-(CH ₂ ) _w O- is particularly preferred.
[0012]
In the general formula (1), S2 represents a connecting chain whose main chain is composed of at least one atom selected from carbon, oxygen, silicon and sulfur. The connecting chain preferably has linear or branched flexibility, and the number of atoms constituting the connecting chain S2 is preferably 5 to 20, and more preferably 5 to 18. Examples of the linking chain include an alkylene chain, an alkenylene chain, an alkynylene chain, an oxyalkylene chain, and an oxyalkylenoyl chain, and among them, those having an alkylene chain are preferable. Further, these linking chains may have a bond such as an ether bond, a thioether bond, an ester bond, an amide bond, an imine bond, a double bond, or a triple bond.
[0013]
Specifically, S2 represents -C (= O) -O- (CH ₂ ) _m -O-, -O (CH ₂ ) _m -O-C (= O)-, -O-C (= O)-(CH ₂ ) _m -O- or -O (CH ₂ ) _m A connecting chain represented by —C (═O) —O— (n represents an integer of 2 to 15) is preferred, and —C (═O) —O— (CH ₂ ) _m -O- or -O (CH ₂ ) _m -O-C (= O)-is particularly preferred.
[0014]
In the general formula (1), A represents a ring selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring. For example, cyclopentane ring, furan ring, pyrrole ring, thiophene ring, thiazole ring, thiadiazole ring, benzene ring, cyclohexane ring (one CH constituting the cyclohexane ring) ₂ Two or more non-adjacent CHs constituting a group or this ring ₂ The group may be replaced by -O- or -S-. ), Cyclohexene ring, pyridine ring, pyrimidine ring, pyrazine ring, piperidine ring, piperazine ring, naphthalene ring, tetralin ring, decalin ring, and the like. Among these, a benzene ring and a cyclohexane ring are preferable.
[0015]
Specifically, for example, 1,4-phenylene ring, 1,4-cyclohexylene ring (one CH constituting the cyclohexylene ring) ₂ Two or more non-adjacent CHs constituting a group or this ring ₂ The group may be replaced by -O- or -S-) 1,3-dioxane-2,5-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2, 5-diyl, piperidine-2,5-diyl, piperidine-1,4-diyl, piperazine-2,5-diyl, 1,4-cyclohexylene, 1,4-cyclohexenylene, naphthalene-2,6- More preferred are rings selected from diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl and 1,4-bicyclo [2.2.2] octylene.
[0016]
Ring A may be further substituted with at least one substituent selected from the group consisting of a halogen group, a cyano group, a hydroxyl group, an alkyl group, an alkoxy group, and an alkanoyl group. Specifically, the halogen group is preferably a fluorine atom, a bromine atom or a chlorine atom, particularly preferably a fluorine atom or a chlorine atom. As the alkyl group, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferable, and a methyl group and an ethyl group are particularly preferable. As an alkoxy group, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group are preferable. The alkanoyl group is preferably an acetyl group, a propionyl group, or a butyryl group.
[0017]
In the general formula (1), M represents a mesogen moiety having at least two rings that are the same or different selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring, and a condensed ring. Although there is no restriction | limiting in particular in the structure of a mesogen part, What has 2-16 rings is preferable, What has 2-8 rings is more preferable, What has 2-4 rings is the most preferable. The number of atoms constituting the ring is not particularly limited and may be 3 or more that can constitute the ring, but the range of 3 to 10 is more preferable.
[0018]
Examples of the ring having 3 to 5 atoms include cyclopropane, oxirane, cyclobutane, cyclopentane, cyclopentanone, tetrahydrofuran, dioxolan-2-one, furan, pyrrole, pyrroline, pyrrolidine, oxazole, isoxazole, Examples include thiophene, thiazole, isothiazole, thiadiazole, imidazole, imidazoline, imidazolidine, pyrazole, pyrazoline, pyrazolidine, 1,2,3-triazole, 1,2,4-triazole, tetrazole, and the like.
[0019]
Examples of the ring having 6 atoms include benzene, pyridine, pyrazine, pyridazine, pyrimidine, 1,2,4-triazine, 1,3,5-triazine, tetrazine, dihydrooxazine, cyclohexane, cyclohexene, cyclohexadiene, Examples include cyclohexanone, piperidine, piperazine, tetrahydropyran, dioxane, tetrahydrothiopyran, dithiane, oxathiane, dioxaborinane and the like.
[0020]
Examples of the ring having 7 or more atoms include naphthalene, dioxanaphthalene, tetralin, quinoline, coumarin, quinoxaline, decalin, indane, benzoxazole, benzothiazole, phenanthrene, dihydrophenanthrene, perhydrophenanthrene, dihydro Examples include oxaperhydrophenanthrene, fluorene, fluorenone, cycloheptane, cycloheptatrienone, and cholesterol.
[0021]
In addition to these, examples of the ring constituting the mesogenic part M include bicyclo (2,2,2) octane and bicyclo (2,2,2) octene as bridged rings. Examples of the ring having a spiro bond include 1,5-dioxaspiro (5,5) undecane and 1,5-dithiaspiro (5,5) undecane.
[0022]
Specifically, the mesogen part M in the general formula (1) preferably has one or more structural units represented by the following general formula (2).
[0023]
E- (Y1-F) n-Y2-G (2)
[0024]
In the above general formula (2), E, F and G are each independently 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, naphthalene-2,6-diyl, deca Hydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, 1,4-bicyclo [2.2.2] octylene, 1,3-dioxane-2,5- Diyl, pyridine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, and pyrimidine-2,5-diyl are represented. The site | part of E couple | bonds with the ring A through connecting chain S2 in the formula represented by the said General formula (1).
[0025]
Further, any part of E, F, G may be substituted with at least one substituent selected from the group consisting of a halogen group, a cyano group, a hydroxyl group, an alkyl group, an alkoxy group, and an alkanoyl group, preferable.
[0026]
As the halogen group, a fluorine atom, a bromine atom and a chlorine atom are preferable, and a fluorine atom and a chlorine atom are particularly preferable. As the alkyl group, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferable, and a methyl group and an ethyl group are particularly preferable. As an alkoxy group, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group are preferable. As the alkanoyl group, an acetyl group, a propionyl group, and a butyryl group are preferable.
[0027]
These substituents are linear or branched chains composed of at least one kind of atoms 1 to 30 selected from carbon, oxygen, silicon, and sulfur, and any of E, F, and G in the mesogenic part. It may be connected to any part. Specific examples of these linking chains include an alkyl chain, an alkylene chain, an alkenylene chain, an alkynylene chain, an oxyalkylene chain, and an oxyalkylenoyl chain. Further, these linking chains may have a bond such as an ether bond, a thioether bond, an ester bond, an amide bond, an imine bond, a double bond, or a triple bond.
[0028]
In the general formula (2), Y 1 and Y 2 are each independently a single bond, —CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -C (= O) O-, -OC (= O)-, -C≡C-, -CH = CH-, -CF = CF-,-(CH ₂ ) _Four -, -CH ₂ CH ₂ CH ₂ O-, -OCH ₂ CH ₂ CH ₂ -, -CH = CH-CH ₂ CH ₂ -, -CH ₂ CH ₂ —CH═CH—, —CH═CH—C (═O) O— or —OC (═O) —CH═CH— is represented, and n represents an integer of 0 to 3. Further, when there are a plurality of Y1 and F, each Y1 and F may be the same or different.
[0029]
Among them, E, F, and G are 1,4-phenylene, Y1 or Y2 is —C≡C—, and the other Y1 or Y2 is a single bond, —C (═O) O—, or —OC A structural unit which is (═O) — is preferred.
[0030]
Examples of the structural unit represented by the general formula (2) include a structural unit represented by the following formula.
[0031]
[Chemical 1]

[0032]
[Chemical formula 2]

[0033]
[Chemical 3]

[0034]
[Formula 4]

[0035]
[Chemical formula 5]

[0036]
[Chemical 6]

[0037]
[Chemical 7]

[0038]
[Chemical 8]

[0039]
[Chemical 9]

[0040]
[Chemical Formula 10]

[0041]
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[0042]
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[0043]
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[0044]
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[0045]
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[0046]
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[0047]
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[0048]
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[0049]
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[0050]
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[0051]
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[0052]
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[0053]
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[0054]
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[0055]
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[0056]
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[0057]
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[0058]
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[0059]
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[0060]
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[0061]
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[0062]
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[0063]
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[0064]
(In formulas (1) to (446), the aromatic ring, alicyclic ring, heterocyclic ring and condensed ring are selected from the group consisting of a cyano group, a halogen atom, an alkyl group having 1 to 7 carbon atoms, an alkoxy group and an alkanoyl group. And may be substituted with one or more substituents.)
[0065]
Specifically, as the polymerizable liquid crystal compound used in the present invention, among the polymerizable liquid crystal compounds represented by the general formula (1), the following general formulas (4) and (5),
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[0066]
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[0067]
(In the formula, X represents a hydrogen atom or a methyl group, and Y 3 represents a single bond, —OC (═O) —, —C (═O) O—, —C≡C— and —CH). ₂ CH ₂ -Represents a linking group selected from the group consisting of:-R represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group; q represents an integer of 1 to 20; M represents an integer of 2 to 15, and p represents an integer of 0 or 1. The 1,4-cyclohexylene group and the 1,4-phenylene group are each independently selected from the group consisting of a cyano group, a halogen atom, an alkyl group having 1 to 7 carbon atoms, an alkoxy group, and an alkanoyl group. It may be substituted with one or more substituents. )
A polymerizable liquid crystal compound represented by:
[0068]
The following general formulas (6), (7) and (8),
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[0069]
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[0070]
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(In the formula, X represents a hydrogen atom or a methyl group, and Y3 and Y4 each independently represent a single bond, —OC (═O) —, —C (═O) O—, —C≡C— And -CH ₂ CH ₂ -Represents a linking group selected from the group consisting of:-R represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group; q represents an integer of 1 to 20; M represents an integer of 3 to 16, and p represents an integer of 0 or 1. In addition, each 1,4-phenylene group may be independently substituted with one or more alkyl groups having 1 to 7 carbon atoms, alkoxy groups, alkanoyl groups, cyano groups, or halogen atoms. )
Polymerizable liquid crystal compounds represented by the following general formulas (9) and (10),
[0071]
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[0072]
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(In the formula, X represents a hydrogen atom or a methyl group, R represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group, and q represents 1 to 20) M represents an integer of 2 to 15. In addition, 1,4-cyclohexylene group and 1,4-phenylene group are each independently a cyano group, a halogen atom, or a carbon atom number of 1. A polymerizable liquid crystal compound represented by formula (11), (12), which may be substituted with one or more substituents selected from the group consisting of alkyl groups, alkoxy groups, and alkanoyl groups: (13), (14) and (15),
[0073]
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[0074]
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[0075]
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[0076]
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[0077]
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[0078]
(Wherein X represents a hydrogen atom or a methyl group, Y 3, Y 4 and Y 5 are each independently a single bond, —OC (═O) —, —C (═O) O—, —C≡). C represents a linking group selected from the group consisting of C— and —CH 2 CH 2 —, q represents an integer of 1 to 20, m represents an integer of 3 to 16, and ring J represents a 1,4-cyclohexylene group. 1,4-phenylene group, R represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group, and p and s are each independently 0 Or 1,4-cyclohexylene group and 1,4-phenylene group are each independently a cyano group, a halogen atom, an alkyl group having 1 to 7 carbon atoms, an alkoxy group and an alkanoyl group. One or more positions selected from the group consisting of It may be substituted with a group.)
The polymerizable liquid crystal compound represented by is particularly preferable.
[0079]
Although the (meth) acrylate compound has been mentioned as a preferable example of the compound of this invention, the compound which has an epoxy group as a reactive group is also preferable. Examples of such compounds include compounds represented by the following general formulas (16) and (17).
[0080]
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[0081]
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[0082]
Wherein Y 3, Y 4 and Y 5 are each independently selected from the group consisting of a single bond, —OC (═O) —, —C (═O) O—, —C≡C— and —CH 2 CH 2 —. Q represents an integer of 1 to 20, m represents an integer of 2 to 15, n represents an integer of 3 to 16, and ring J represents a 1,4-cyclohexylene group. 1,4-phenylene group, R represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group, and p and s are each independently 0 or In addition, 1,4-cyclohexylene group and 1,4-phenylene group each independently comprise a cyano group, a halogen atom, an alkyl group having 1 to 7 carbon atoms, an alkoxy group, and an alkanoyl group. One or more substitutions selected from the group In may be substituted.)
[0083]
As a preferred example of the compound of the present invention, a compound having a vinyloxy group as a reactive group is also preferred. Examples of such compounds include compounds represented by the following general formulas (18) and (19).
[0084]
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[0085]
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[0086]
Wherein Y 3, Y 4 and Y 5 are each independently selected from the group consisting of a single bond, —OC (═O) —, —C (═O) O—, —C≡C— and —CH 2 CH 2 —. Q represents an integer of 1 to 20, m represents an integer of 2 to 15, ring J represents a 1,4-cyclohexylene group, a 1,4-phenylene group, R Represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group, and p and s each independently represent 0 or 1. In addition, 1,4- The cyclohexylene group and the 1,4-phenylene group are each independently one or more substituents selected from the group consisting of a cyano group, a halogen atom, an alkyl group having 1 to 7 carbon atoms, an alkoxy group, and an alkanoyl group. May be replaced with.)
[0087]
As a preferred example of the compound of the present invention, a compound having a maleimide group as a reactive group is also preferred. Examples of such compounds include compounds represented by the following general formulas (20) and (21).
[0088]
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[0089]
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[0090]
Wherein Y 3, Y 4 and Y 5 are each independently selected from the group consisting of a single bond, —OC (═O) —, —C (═O) O—, —C≡C— and —CH 2 CH 2 —. Q represents an integer of 1 to 20, m represents an integer of 2 to 15, ring J represents a 1,4-cyclohexylene group, a 1,4-phenylene group, R Represents a hydroxyl group, a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group or an alkanoyl group, and p and s each independently represent 0 or 1. In addition, 1,4- The cyclohexylene group and the 1,4-phenylene group are each independently one or more substituents selected from the group consisting of a cyano group, a halogen atom, an alkyl group having 1 to 7 carbon atoms, an alkoxy group, and an alkanoyl group. May be replaced with.)
[0091]
The liquid crystal composition of the present invention preferably exhibits a liquid crystal phase at room temperature, typically 25 ° C., when applied to the production of an optical element.
[0092]
The liquid crystal composition of the present invention may be any composition that exhibits a phase that is generally recognized as a liquid crystal phase in this technical field. Among such compositions, those exhibiting a nematic phase, a smectic A phase, a (chiral) smectic C phase, and a cholesteric phase are preferable as the liquid crystal phase. Among them, the nematic phase is particularly preferable because it has good orientation. When a (chiral) smectic C phase is shown, the smectic A phase is higher than the temperature range of the (chiral) smectic C phase, and the nematic phase is higher than the temperature range of the smectic A phase. Each of the liquid crystal compositions that are expressed is preferable because it tends to obtain good alignment.
[0093]
The liquid crystal composition of the present invention can also be used in combination with known and commonly used liquid crystal compounds. Among them, a polymerizable functional group selected from the group consisting of one (meth) acryloyloxy group, (meth) acrylamide group, vinyl group, epoxy group, ethynyl group, mercapto group, vinyloxy group and maleimide group in one molecule. The liquid crystalline compound having is preferable. As such a polymerizable liquid crystal compound, for example, the general formula (3)
[0094]
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[0095]
(In the formula, X represents a hydrogen atom or a methyl group, M represents a mesogenic moiety having 2 to 16 identical or different rings selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring; Y _Three Represents a linking group selected from the group consisting of a single bond, —O—, —OC (═O) —, —C (═O) O— and —CH═CH—C (═O) O—, and Z ₁ Represents a hydrogen atom, a halogen atom, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms. )
And a polymerizable liquid crystal compound represented by the formula:
[0096]
In the general formula (2), the mesogen part M has the same structure as the mesogen part M in the general formula (1).
[0097]
Specifically, for example, the following general formula (22)
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(In the formula, X represents a hydrogen atom or a methyl group, r represents an integer of 0 or 1, 6-membered rings K, L, and M are each independently a 1,4-phenylene group, pyridine- 2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, 1,4-cyclohexylene group, one or two non-adjacent CH ₂ Represents a 1,4-cyclohexylene group or 1,4-cyclohexenyl group in which the group is substituted with an oxygen or sulfur atom, and these 6-membered rings K, L and M are further a cyano group, a halogen atom, a carbon atom May be substituted with one or more substituents selected from the group consisting of alkyl groups, alkoxy groups and alkanoyl groups of formulas 1 to 7; ₁ And Y ₂ Are each independently a single bond, —CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -C (= O) O-, -OC (= O)-, -C≡C-, -CH = CH-, -CF = CF-,-(CH ₂ ) _Four -, -CH ₂ CH ₂ CH ₂ O-, -OCH ₂ CH ₂ CH ₂ -, -CH = CH-CH ₂ CH ₂ -, -CH ₂ CH ₂ Y represents a linking group selected from the group consisting of —CH═CH—, —CH═CH—C (═O) O— and —OC (═O) —CH═CH—, and Y _Three Represents a linking group selected from the group consisting of a single bond, —O—, —OC (═O) —, —C (═O) O— and —CH═CH—C (═O) O—, and Z ₁ Represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms, or an alkenyl group having 2 to 20 carbon atoms. )
The liquid crystalline (meth) acrylate represented by
[0098]
As the liquid crystalline (meth) acrylate compound represented by the general formula (22) that can be contained in the liquid crystal composition of the present invention, the general formula (23),
[0099]
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[0100]
(In the formula, X represents a hydrogen atom or a methyl group, R ₁ Represents an alkyl group having 1 to 10 carbon atoms. )
A compound represented by the general formula (24),
[0101]
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[0102]
(In the formula, X represents a hydrogen atom or a methyl group, R ₂ Represents an alkyl group having 1 to 10 carbon atoms. )
The compound represented by these is preferable. These compounds represented by the general formula (23) and the compound represented by the general formula (24) may be used alone or in combination. When used in combination, it is preferable that the concentrations of the compounds represented by the general formula (23) and the general formula (24) are equal. The amount used is preferably 90% by weight or less, and more preferably 80% by weight or less. However, compounds that can be used in the liquid crystal composition of the present invention are not limited to these compounds.
[0103]
Specific examples of the compound represented by the general formula (22) include compounds represented by the formulas (a-1) to (a-25). In addition, the phase transition temperature was shown under the structural formula of the compound represented by the illustrated formula (a-1)-formula (a-25). (In the formula, the cyclohexane ring represents a transcyclohexane ring. The number represents a phase transition temperature, C represents a crystalline phase, N represents a nematic phase, S represents a smectic phase, and I represents an isotropic liquid phase.)
[0104]
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[0105]
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[0106]
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[0107]
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[0108]
In addition to the (meth) acrylate compound represented by the general formula (22), the liquid crystal composition of the present invention may contain other monofunctional (meth) acrylate compounds. Examples of such compounds include compounds represented by the following formulas (a-26) to (a-35). However, compounds that can be used in the liquid crystal composition of the present invention are not limited thereto. In addition, the phase transition temperature was shown under the structural formula of the compound represented by the illustrated formula (a-26) to formula (a-35). (In the formula, the cyclohexane ring represents a transcyclohexane ring. The number represents a phase transition temperature, C represents a crystalline phase, N represents a nematic phase, S represents a smectic phase, and I represents an isotropic liquid phase.)
[0109]
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[0110]
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[0111]
In addition to the compounds listed above, the liquid crystal composition of the present invention may contain a (meth) acrylate compound having a liquid crystalline skeleton in the side chain. Examples of such a compound include compounds represented by the following formulas (a-36) to (a-45). (In the formula, the cyclohexane ring represents a transcyclohexane ring. The number represents a phase transition temperature, C represents a crystalline phase, N represents a nematic phase, S represents a smectic phase, and I represents an isotropic liquid phase.)
[0112]
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[0113]
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[0114]
Furthermore, in addition to the compounds listed above, the liquid crystal composition of the present invention may contain other liquid crystalline (meth) acrylate compounds in the liquid crystal composition of the present invention. Examples of such a compound include compounds represented by the following formulas (a-46) to (a-61).
[0115]
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[0116]
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(Where X ⁶ And X ⁷ Each independently represents a hydrogen atom or a methyl group, and s and t each independently represents an integer of 2 to 18).
[0117]
Moreover, the liquid crystal compound which does not have a polymerizable functional group can also be added to the liquid-crystal composition of this invention according to a use. However, from the viewpoint of ensuring the heat resistance of the polymer produced using the liquid crystal composition, the amount added is preferably 80% by weight or less, more preferably 30% by weight or less, and particularly preferably 10% by weight or less.
[0118]
In addition, a compound that has a polymerizable functional group and does not exhibit liquid crystallinity can be added to the liquid crystal composition of the present invention. Such a compound can be used without particular limitation as long as it is generally recognized as a polymer-forming monomer or polymer-forming oligomer in this technical field.
[0119]
The liquid crystal composition of the present invention is intended to polymerize the polymerizable compound in the composition by irradiating active energy rays in the temperature region of the liquid crystal phase. Therefore, the liquid crystal composition of the present invention is produced at room temperature (typically 25 ° C.) or room temperature in order to avoid undesired thermal polymerization in the active energy ray irradiation process and to produce a polymer having excellent uniformity. What shows liquid crystallinity near is preferable. For example, in the (chiral) smectic C phase, when the polymerizable compound in the composition is polymerized by irradiating the liquid crystal composition of the present invention with active energy rays, the (chiral) smectic C phase is expressed at or near room temperature. Those that do are preferred.
[0120]
In addition, a chiral (optically active) compound can be added to the liquid crystal composition of the present invention for the purpose of obtaining a polymer having a helical structure of a liquid crystal skeleton inside. The chiral compound used for such a purpose does not need to exhibit liquid crystal properties per se, and may or may not have a polymerizable functional group. Moreover, the direction of the spiral of the chiral compound can be appropriately selected depending on the intended use of the polymer.
[0121]
As such a chiral compound, for example, “CB-” manufactured by BD H. Co. (BDH; UK) having cholesteryl group as a chiral group, cholesterol stearate and 2-methylbutyl group as a chiral group. 15 ”,“ C-15 ”,“ S-1082 ”manufactured by Merck (Germany),“ CM-19 ”,“ CM-20 ”,“ CM ”manufactured by Chisso; 1-methylheptyl as a chiral group Examples thereof include “S-811” manufactured by Merck Co., which has a group, “CM-21” and “CM-22” manufactured by Chisso Corporation.
[0122]
A preferable addition amount in the case of adding a chiral compound depends on the use of the liquid crystal composition, but is a value obtained by dividing the thickness (d) of the polymer obtained by polymerization by the helical pitch (P) in the polymer (d / P) is preferably in the range of 0.1 to 100, more preferably in the range of 0.1 to 20.
[0123]
Furthermore, for the purpose of improving the polymerization reactivity, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator can be added to the liquid crystal composition of the present invention.
Examples of the thermal polymerization initiator include benzoyl peroxide and bisazobutyronitrile. Examples of the photopolymerization initiator include benzoin ethers, benzophenones, acetophenones, and benzyl ketals. In the case of adding a thermal polymerization initiator or a photopolymerization initiator, the addition amount is preferably 10% by weight or less, particularly preferably 5% by weight or less, and 0.5 to 1.5% by weight with respect to the liquid crystal composition. A range is more preferred.
[0124]
In addition, a stabilizer can be added to the liquid crystal composition of the present invention in order to improve its storage stability. Examples of the stabilizer that can be used include hydroquinone, hydroquinone monoalkyl ethers, tert-butylcatechols, pyrogallols, thiophenols, nitro compounds, β-naphthylamines, β-naphthols, and the like. When the stabilizer is used, the amount added is preferably 1% by weight or less, particularly preferably 0.5% by weight or less, based on the liquid crystal composition.
[0125]
As described above, in the liquid crystal composition of the present invention, in addition to the liquid crystalline (meth) acrylate represented by the general formula (1) or (2), a liquid crystal compound having a polymerizable functional group, a polymerizable functional group A liquid crystal compound having no liquid crystal, a polymerizable compound that does not exhibit liquid crystallinity, a polymerization initiator, and a stabilizer may be added in appropriate combination, but at least each component is selected so that the liquid crystal properties of the obtained liquid crystal composition are not lost. It is necessary to adjust the amount of addition.
[0126]
Further, when the liquid crystal composition of the present invention is used for a polarizing film or a raw material for an alignment film, or for printing inks and paints, protective films, etc., depending on the purpose, a metal, a metal complex, a dye, a pigment, Dyes, fluorescent materials, phosphorescent materials, surfactants, leveling agents, thixotropic agents, gelling agents, polysaccharides, ultraviolet absorbers, infrared absorbers, antioxidants, ion exchange resins, metal oxides such as titanium oxide, etc. It can also be added.
[0127]
The liquid crystal composition containing the liquid crystal compound of the present invention is polymerized to form a polymer, so that a retardation plate, a polarizing plate, a polarizing prism, a waveguide, a piezoelectric element, a nonlinear optical element, various optical filters, a cholesteric liquid crystal phase, etc. For various applications such as liquid crystal pigments, liquid crystal-resin composite displays, holographic liquid crystal displays, polymer-stabilized liquid crystal (ferroelectric liquid crystals, antiferroelectric liquid crystal) displays, optical fiber coatings, etc. Can be applied. Among them, in the state where the liquid crystal composition of the present invention is aligned, the polymerized polymer has anisotropy in physical properties and is useful. Such a polymer is, for example, a substrate obtained by rubbing the surface of the polymerizable liquid crystal composition of the present invention with a cloth, a substrate obtained by rubbing the surface of a substrate on which an organic thin film is formed, or a SiO 2 ₂ Can be produced by polymerizing a polymerizable compound after it is supported on a substrate having an alignment film deposited obliquely or sandwiched between substrates.
[0128]
Examples of the method for supporting the polymerizable liquid crystal composition on the substrate include spin coating, die coating, extrusion coating, roll coating, wire bar coating, gravure coating, spray coating, dipping, and printing. It is done. Further, an organic solvent can be added to the polymerizable liquid crystal composition during coating. Examples of the organic solvent that can be used for such purposes include ethyl acetate, tetrahydrofuran, toluene, hexane, methanol, ethanol, dimethylformamide, methylene chloride, isopropanol, acetone, methyl ethyl ketone, acetonitrile, cellosolves, and the like. It is done. These organic solvents can be used singly or in combination of two or more, and may be appropriately selected in consideration of the vapor pressure and the solubility of the polymerizable liquid crystal composition. The amount of the organic solvent added is preferably 90% by weight or less of the coating material. If it is 90% by weight or more, the resulting film thickness tends to be thin, such being undesirable.
[0129]
As a method for volatilizing the added organic solvent, natural drying, heat drying, reduced pressure drying, or reduced pressure heat drying can be used. In order to further improve the applicability of the polymerizable liquid crystal material, a method of providing an intermediate layer such as a polyimide thin film on the substrate and a method of adding a leveling agent to the polymerizable liquid crystal material are also effective. In particular, the method of providing an intermediate layer such as a polyimide thin film on a substrate is effective as a means for improving adhesion when the adhesion between a polymer obtained by polymerizing a polymerizable liquid crystal material and the substrate is not good. .
[0130]
Examples of a method for sandwiching the polymerizable liquid crystal material between the substrates include an injection method using a capillary phenomenon. It is also effective to depressurize the space formed between the substrates and then inject a polymerizable liquid crystal material.
[0131]
Rubbing treatment or SiO ₂ Examples of the alignment treatment method other than oblique vapor deposition include a method using flow alignment of a liquid crystal material and a method using an electric field or a magnetic field. These orientation means can be used alone or in combination of two or more methods.
[0132]
Furthermore, a photo-alignment method can be used as an alignment treatment method instead of rubbing. This method can be applied to, for example, an organic thin film having a functional group that undergoes photodimerization reaction in a molecule such as polyvinyl cinnamate, an organic thin film having a functional group that is isomerized by light, or an organic thin film such as polyimide. An alignment film is formed by irradiating polarized ultraviolet rays. By applying an optical mask to this photo-alignment method, patterning of the alignment can be easily achieved, so that the molecular orientation inside the polymer can also be precisely controlled.
[0133]
The shape of the substrate may be a curved surface in addition to a flat plate. The material which comprises a board | substrate can be used regardless of an organic material and an inorganic material. Examples of the organic material used as the substrate material include polyethylene terephthalate, polycarbonate, polyimide, polyamide, polymethyl methacrylate, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyarylate, polysulfone, and triacetyl. Cellulose, cellulose, polyetheretherketone and the like can be mentioned, and examples of the inorganic material include silicon, glass and calcite.
[0134]
When appropriate orientation cannot be obtained by rubbing these substrates with a cloth or the like, an organic thin film such as a polyimide thin film or a polyvinyl alcohol thin film is formed on the substrate surface according to a known method, and this is rubbed with a cloth or the like. Also good. In addition, the polyimide thin film that gives a pretilt angle used in a normal twisted nematic (TN) element or a super twisted nematic (STN) element can control the molecular orientation structure inside the polymer more precisely. Are particularly preferred.
[0135]
In the case where the alignment state is controlled by an electric field, a substrate having an electrode layer is used. In this case, it is preferable to form an organic thin film such as the aforementioned polyimide thin film on the electrode.
[0136]
The alignment state of the liquid crystal composition may be various alignment states generally known in the technical field of liquid crystal, for example, homogeneous (horizontal) alignment, tilted homogeneous alignment, homeotropic (vertical) alignment, tilted. Examples thereof include homeotropic alignment, hybrid alignment, twisted nematic alignment, and super twisted nematic alignment. Moreover, you may pattern by changing the orientation state for the combination of these orientations or every place.
[0137]
In the case of tilted homogeneous alignment and tilted homeotropic alignment, it means that the angle between the substrate surface and the major axis of the liquid crystal molecule is other than 0 degrees or 90 degrees in both cases. The angle formed between the substrate surface and the major axis of the liquid crystal molecules may be selected depending on the intended use and function of the polymer obtained. When the angle formed between the substrate surface and the major axis of the liquid crystal molecules is set in the range of 10 to 80 degrees, more preferably in the range of 20 to 70 degrees, the resulting polymer is an optical member for widely improving the viewing angle of the liquid crystal display Can be used as
[0138]
In addition, when the alignment state of the liquid crystal composition is hybrid alignment, the obtained polymer can be used as an optical member for widely improving the viewing angle of the liquid crystal display. In addition, when the angle between the substrate surface and the major axis of the liquid crystal molecules is set to 30 to 60 degrees, more preferably 40 to 50 degrees, and particularly preferably 45 degrees, the obtained polymer is efficiently imparted with polarization separation ability. can do. Such a polymer is useful as a polarization separation element or an optical low-pass filter.
[0139]
Further, when the alignment state of the liquid crystal composition is hybrid alignment, the obtained polymer is useful as a polarizing optical element or an optical low-pass filter.
On the other hand, an alignment structure having a helical structure represented by twisted nematic alignment, super twisted nematic alignment, and cholesteric alignment is also useful. When the twist angle is set to 60 to 270 degrees, the obtained polymer is useful for optical compensation for liquid crystal display elements. In addition, when the helical pitch is adjusted so as to selectively reflect a specific wavelength region, the obtained polymer is useful as a notch filter or a reflective color filter.
[0140]
Moreover, when the wavelength region which selectively reflects is set to the infrared region, the obtained polymer is useful as a heat ray cut filter. In addition, when it is in a homogeneous orientation or homeotropic orientation state, the obtained polymer has a greater refractive index anisotropy than that obtained by stretching a plastic, and therefore exhibits the same refractive index anisotropy. There is an advantage that can be designed thin. There is also a possibility that an optical compensator can be built in the liquid crystal cell. This characteristic is important when used for optical compensation of a reflective liquid crystal display element, and is particularly useful as a quarter-wave plate.
[0141]
As a method of polymerizing the liquid crystal composition of the present invention, a method of polymerizing by irradiating active energy rays such as ultraviolet rays or an electron beam is preferable in terms of rapid polymerization. When ultraviolet rays are used, a polarized light source or a non-polarized light source may be used. Further, when the polymerization is performed with the liquid crystal composition sandwiched between two substrates, at least the substrate on the irradiation surface side must be given appropriate transparency to the active energy rays. Moreover, after polymerizing only a specific part using a mask at the time of light irradiation, the orientation state of the unpolymerized part is changed by changing conditions such as an electric field, a magnetic field, or temperature, and further irradiation with active energy rays is performed. Then, it is possible to use a means for polymerization. Moreover, it is preferable that the temperature at the time of irradiation is in the temperature range in which the liquid crystal state of the liquid crystal composition of the present invention is maintained.
[0142]
In particular, when a polymer is to be produced by photopolymerization, the polymerization is carried out at a temperature as close to room temperature as possible, that is, typically at a temperature of 25 ° C., from the viewpoint of avoiding unintentional induction of thermal polymerization. It is preferable. The intensity of the active energy ray is 0.1 mW / cm ² ~ 2W / cm ² The range of is preferable. Strength is 0.1mW / cm ² If it is less than 2, much time is required to complete the photopolymerization, and the productivity tends to deteriorate. ² If the strength exceeds 1, the polymerizable liquid crystal composition tends to deteriorate, which is not preferable.
[0143]
After irradiating the polymerizable liquid crystal composition of the present invention with actinic rays, heat treatment can be applied for the purpose of reducing the initial characteristic change of the obtained polymer and achieving stable characteristic expression. The heat treatment temperature is preferably in the range of 50 to 250 ° C., and the heat treatment time is preferably in the range of 30 seconds to 12 hours.
[0144]
The polymer comprising the polymerizable liquid crystal composition of the present invention produced by such a method can be peeled off from the substrate and used alone or can be used as it is without being peeled off from the substrate. Moreover, the polymer which consists of a polymeric liquid crystal composition of this invention can be used by laminating | stacking 2 or more, and can also be bonded together and used for another board | substrate.
[0145]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In addition, the measurement of the haze in the following Examples was performed by the compensation method (JIS, K7361).
[0146]
Example 1 [Preparation of Liquid Crystal Composition (1)]
Formula (a-1)
[0147]
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45 parts by weight of a liquid crystal acrylate compound represented by the formula (a-4)
[0148]
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45 parts by weight of a liquid crystalline acrylate represented by the formula (a-62)
[0149]
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The composition (A) which consists of 10 weight part of liquid crystalline acrylate represented by these was prepared. The composition (A) exhibited a nematic liquid crystal phase at room temperature (25 ° C.). N measured at 589 nm _e (Refractive index of extraordinary light) is 1.6702, n _o The refractive index of ordinary light was 1.511, and the birefringence was 0.1592.
[0150]
(Example 2) [Preparation of liquid crystal composition (2)]
35 parts by weight of a liquid crystal acrylate compound represented by the formula (a-1) in Example 1, 35 parts by weight of a liquid crystal acrylate represented by the formula (a-4) and a liquid crystal acrylate represented by the formula (a-62) A composition (B) consisting of 30 parts by weight was prepared. The composition (B) exhibited a nematic liquid crystal phase at room temperature (25 ° C.). N measured at 589 nm _e (Refractive index of extraordinary light) is 1.6813, n _o The refractive index of ordinary light was 1.512, and the birefringence was 0.1693.
[0151]
(Comparative Example 1) [Preparation of liquid crystal composition (3)]
A composition (C) comprising 50 parts by weight of the liquid crystalline acrylate compound represented by the formula (a-1) in Example 1 and 50 parts by weight of the liquid crystalline acrylate represented by the formula (a-4) was prepared. The composition (C) exhibited a nematic liquid crystal phase at room temperature (25 ° C.). The nematic phase-isotropic liquid phase transition temperature was 46 ° C. N measured at 589 nm _e (Refractive index of extraordinary light) is 1.661, n _o The refractive index of ordinary light was 1.510, and the birefringence was 0.152.
[0152]
(Example 3) [Production of optical anisotropic body (1)]
A composition (D) comprising 99 parts by weight of the composition (A) prepared in Example 1 and 1 part by weight of a photopolymerization initiator “Irgacure 651” (manufactured by Ciba Geigy) was prepared. The composition (D) was injected at room temperature into an anti-parallel alignment liquid crystal glass cell having a cell gap of 5 and 50 microns (a glass cell subjected to alignment treatment so that the liquid crystal was uniaxially aligned). It was confirmed that uniform uniaxial orientation was obtained after the injection. Next, 30 mW / cm using a UIS-25102 of USHIO at room temperature (25 ° C.) ² Of UV rays of 90, 180 and 360 mJ / cm ² It irradiated until it became, and the composition (D) was polymerized and the polymer was obtained. It was confirmed that the obtained polymer had different refractive indexes depending on directions and functioned as an optical anisotropic body. Table 1 shows the transparency (haze value) and retardation of the polymer as put in the glass cell.
[0153]
[Table 1]
Haze and retardation of polymer of composition (D)

[0154]
(Example 4) [Production of optical anisotropic body (2)]
A composition (E) comprising 99 parts by weight of the composition (B) prepared in Example 2 and 1 part by weight of a photopolymerization initiator “Irgacure 651” (manufactured by Ciba Geigy) was prepared. The composition (E) was injected at room temperature into an anti-parallel alignment liquid crystal glass cell having a cell gap of 5 and 50 microns (a glass cell subjected to alignment treatment so that the liquid crystal was uniaxially aligned). After injection, it was confirmed that uniform uniaxial orientation was obtained quickly. Next, 30 mW / cm using a UIS-25102 of USHIO at room temperature (25 ° C.) ² Of UV rays of 90, 180 and 360 mJ / cm ² It irradiated until it became, and the composition (E) was polymerized and the polymer was obtained. It was confirmed that the obtained polymer had different refractive indexes depending on directions and functioned as an optical anisotropic body. Table 2 shows the haze and retardation of the polymer as it was put in the glass cell.
[0155]
[Table 2]
Haze and retardation of polymer of composition (E)

[0156]
(Comparative example 2) [Production of optical anisotropic body (3)]
A composition (F) comprising 99 parts by weight of the composition (C) prepared in Comparative Example 1 and 1 part by weight of a polymerization initiator “Irgacure 651” (manufactured by Ciba Geigy) was prepared. The composition (F) was injected at room temperature into an anti-parallel alignment liquid crystal glass cell having a cell gap of 5 and 50 microns (a glass cell subjected to alignment treatment so that the liquid crystal was uniaxially aligned). It was confirmed that uniform uniaxial orientation was obtained after the injection. Next, 30 mW / cm using a UIS-25102 of USHIO at room temperature (25 ° C.) ² Of UV rays of 90, 180 and 360 mJ / cm ² It irradiated until it became, and the composition (F) was polymerized and the polymer was obtained. It was confirmed that the obtained polymer had different refractive indexes depending on directions and functioned as an optical anisotropic body. Table 3 shows the haze and retardation of the polymer as it was put in the glass cell.
[0157]
[Table 3]
Haze and retardation of polymer of composition (F)

The results of Examples 3 and 4 and Comparative Example 2 are shown in Tables 1, 2 and 3. By using the liquid crystal composition containing the compound of the present invention, the haze of the polymer produced by polymerization is reduced. Moreover, it turns out that the retardation was improved.
[0158]
【Effect of the invention】
The polymerizable liquid crystal composition of the present invention exhibits good liquid crystallinity, and can improve the haze and retardation of a polymer obtained by polymerization. Therefore, the compound of the present invention is, for example, a coating material such as a retardation plate, a polarizing plate, a polarizing prism, a waveguide, a piezoelectric element, a nonlinear optical element, various optical filters, a pigment utilizing selective reflection of a cholesteric liquid crystal phase, an optical fiber and the like. It is extremely useful for application.

Claims (6)

General formula (1)
P-S1-A-S2-M (1)
(P represents a polymerizable functional group of an acryloyloxy group, a methacryloyloxy group, an epoxy group, a vinyloxy group or a maleimide group, and A represents a ring selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring. The mesogenic part M is represented by the following general formula (2)
E- (Y1-F) n-Y2-G (2)
Wherein E, F and G are each independently 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, naphthalene-2,6-diyl, decahydronaphthalene-2 , 6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, 1,4-bicyclo [2.2.2] octylene, 1,3-dioxane-2,5-diyl, pyridine- 2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, or pyrimidine-2,5-diyl, each of Y 1 and Y 2 is independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —C (═O) O—, —OC (═O) —, —C≡C—, —CH═CH—, —CF═CF—, — _{(CH 2) 4 -, -} CH 2 CH 2 CH 2 O-, -OCH 2 CH 2 H2 -, - CH = CH- CH 2 CH 2 -, - CH 2 CH 2 -CH = CH -, - CH = CH-C (= O) O- or -OC the (= O) -CH = CH- N represents an integer of 0 to 3. When there are a plurality of Y1 and F, each Y1 and F may be the same or different.) S1 is — (CH _{2 ) w -, - (CH 2} ) wO -, - (CH 2) wC (= O) O-, and _{- (CH 2) wOC (=} O) - (w is an integer of 1 to 20). represents a linking chain selected from the group consisting of, S2 is, -C (= O) -O- ( CH 2) m-O -, - O (CH 2) m-O-C (= O) -, - O—C (═O) — (CH ₂ ) m —O— and —O (CH ₂ ) m —C (═O) —O— (where m represents an integer of 2 to 15). Represents a connecting chain selected from And a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having one polymerizable functional group in one molecule. As the compound represented by the general formula (1), ring A is 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 1,3-dioxane-2, 5-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl, piperidine-2,5-diyl, piperidine-1,4-diyl, piperazine-2,5- Diyl, 1,4-cyclohexylene, 1,4-cyclohexenylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6 The polymerizable liquid crystal composition according to claim 1, wherein a compound having a ring structure selected from the group consisting of -diyl and 1,4-bicyclo [2.2.2] octylene is used. As the mesogenic part M represented by the general formula (2), E, F and G are 1,4-phenylene, Y1 or Y2 is —C≡C—, and the other Y1 or Y2 is a single bond, The polymerizable liquid crystal composition according to claim 2 , which is —C (═O) O— or —OC (═O) —. Furthermore, one polymerizable functional group selected from the group consisting of one (meth) acryloyloxy group, (meth) acrylamide group, vinyl group, epoxy group, ethynyl group, mercapto group, vinyloxy group and maleimide group in one molecule. The polymerizable liquid crystal composition according to any one of claims 1 to 3 , comprising a liquid crystal compound. A liquid crystal compound having one polymerizable functional group in one molecule is represented by the following general formula (3),

(In the formula, X represents a hydrogen atom or a methyl group, M represents a mesogenic moiety having 2 to 16 identical or different rings selected from the group consisting of an aromatic ring, an alicyclic ring, a heterocyclic ring and a condensed ring; Y 3 represents a linking group selected from the group consisting of a single bond, —O—, —OC (═O) —, —C (═O) O—, and —CH═CH—C (═O) O—. Z 1 represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms, or an alkenyl group having 2 to 20 carbon atoms.)
The polymerizable liquid crystal composition according to claim 4 , which is a compound represented by the formula: An optical element using the polymerizable liquid crystal composition according to claim 1 .